Revert "uclient: Update to version 2020-06-17"

This reverts commit 0c910d8459.

We cannot use uclient Git HEAD as-is on 19.07 due to an older
version of the ustream-ssl API.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

package/libs/uclient/Makefile

@@ -5,9 +5,9 @@ PKG_RELEASE=1
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(PROJECT_GIT)/project/uclient.git
-PKG_MIRROR_HASH:=05962d4edbe7b856e017d974c3d7e34dfa5f905821ab7a3534acc5886af4e5c7
-PKG_SOURCE_DATE:=2020-06-17
-PKG_SOURCE_VERSION:=c66098611f16806a936a3a3f92113a16382fc4d9
+PKG_MIRROR_HASH:=b1127b28f98c9b45e046a76086b281b35c094fad1dc511ce0af095b733c86359
+PKG_SOURCE_DATE:=2019-05-30
+PKG_SOURCE_VERSION:=3b3e368dead01979e985cb167873fe9868b15d19
 CMAKE_INSTALL:=1
 
 PKG_BUILD_DEPENDS:=ustream-ssl